The products of organic thin film transistor (OTFT) driven displays and electronic papers have been gradually entered into the market. An active layer of the OTFT is an organic active layer made by an organic semiconductor material.
The active layer may be made of small organic molecule and polymer semiconductor materials that have high migration rate, good solution processing ability, and stable environment providing ability. With the ongoing and in-depth study of the OTFT, it has been found that the carriers in the OTFT are conducted by a transition mode due to the existing of the intermolecular forces in the organic semiconductor materials. The organic semiconductors are being in a “molecular solid” form. Such special form can make the organic active layer made by an organic semiconductor be more susceptible by the insulating layer resulting in significant changes in the carrier mobility, thus affecting the performances of the OTFT devices.
To solve the problem that the organic active layer made by an organic semiconductor is susceptible from the insulating layer and causes significant changes in the carrier mobility, an organic polymer material is usually used as the insulating layer of an OTFT. However, the dielectric constant of the organic polymer material is relatively low. When the organic polymer material is used alone as the insulating layer of an OTFT device, the threshold voltage of the OTFT device is relatively high, and the leakage current is relatively large.
Accordingly, it is desirable to provide an organic thin film transistor, and a fabricating method thereof to at least partially alleviate one or more problems set forth above and to solve other problems in the art.